Reduction gears are often used in window winders that raise and lower a window in an automobile. These reduction gears adjust the rotational speed of a motor to adjust the drive speed of the window.
Document FR-A-2 771 469 describes a gear motor fitted with a motor, a helical reduction gear and a worm coupled to the motor, and a cable driving drum coupled to the reduction gear wheel. This type of gear motor is costly and requires complex gearing. Moreover, the transmission efficiency of the reduction gear is low.
Document FR 2 815 994 describes a gear motor fitted with a motor, a planetary reduction gear and a cable driving drum coupled to the reduction gear wheel. The reduction gear used is costly, noisy and made up of many parts.
There is therefore a need for a reduction gear and a reduction gear window winder that overcomes one or more of these disadvantages.